1. Field
Embodiments of the present invention relate to an amine-based compound and an organic light-emitting diode including the same.
2. Description of the Related Art
Organic light-emitting diodes (OLEDs), which are self-emitting diodes, have advantages such as wide viewing angles, good contrast, quick response, high brightness, good driving voltage characteristics, and an ability to provide multicolored images.
A typical OLED has a structure including a substrate, and an anode, a hole transport layer, an emission layer (EML), an electron transport layer, and a cathode, which are sequentially stacked on the substrate. The hole transport layer, the emission layer, and the electron transport layer are organic thin films formed of organic compounds.
An operating principle of an OLED having the above-described structure is as follows. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the emission layer via the hole transport layer, and electrons injected from the cathode move to the emission layer via the electron transport layer. The holes and electrons (carriers) recombine in the organic EML to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted.
Korean Patent Publication No. 10-2012-0052993 provides examples of aromatic amine derivatives and suggests that binding of a benzene ring bound to a carbazole group at a para position leads to a low-voltage driving. In addition, when a benzene ring is bound at that para position, a driving voltage of the organic EL device is reduced. This may be because charge mobility is increased by expansion of a conjugated system.
According to Korean Patent Publication No. 10-2012-0052993, of Formula (III), the following Formula (III′) appears to be preferred:

In Formula (III′), X, R5, R6, R7, n, q, r, and s are as defined in the Korean Patent Publication No. 10-2012-0052993.
However, as disclosed in the present specification, it is found that when a benzene ring bound to a carbazole group of an aromatic amine derivative binds only at a para position, such as those according to Korean Patent Publication No. 10-2012-0052993, efficiency and lifespan of a diode are reduced.